<!DOCTYPE html>
<html lang="zh-cn">
<head>
	<meta charset="utf-8">
	<title>035-盒模型内容-百分比设置.html</title>
	<style>
		.father{
			width: 400px;
			height: 400px;
			background: gray;
		}
		.son{
			width: 100%;
			/*width: 200px;*/
			width: 25%;
			/*height: 200px;*/
			height: 25%;
			/*height: 200px;*/
			background: red;
		}
	</style>
</head>
<body>
	<div class="father">
		<div class="son">这是内容</div>
	</div>
</body>
</html>